Lovol 1004-4, User Handbook Manual, Page: 60 / 87

Introduction to the Linear Pumps Made in China
The fuel circuit of the pump is shown in Fig. 1.
The pump camshaft is driven by the engine through the shaft coupling or transmission gears.
Driven by the camshaft, the fuel supply pump sucks the fuel from the tank and supply it to the filter with a pressure of
1.8 to 2.5 kg/cm2. Finally the fuel flows to the fuel housing in the pump body.
The plunger piston is lifted with the turning of the camshaft. As a result the fuel pressure keeps increasing.
The high-pressure fuel is pumped by the fuel pump and injected into the combustion chamber after flowing through
the fuel pipes.
The amount of the fuel supplied by the pump is at least twice the amount of the fuel injected. So the excessive fuel
can flow through the overflow valve to the fuel tank in case the fuel pressure is larger than the required value.
The excessive fuel injected by the injectors (it can also lubricate the injector body) flows to the fuel tank through the
overflow valve on the injector body.
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